diff options
Diffstat (limited to 'arch/x86/include/asm/io_bitmap.h')
| -rw-r--r-- | arch/x86/include/asm/io_bitmap.h | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/arch/x86/include/asm/io_bitmap.h b/arch/x86/include/asm/io_bitmap.h index 07344d82e88e..7f080f5c7def 100644 --- a/arch/x86/include/asm/io_bitmap.h +++ b/arch/x86/include/asm/io_bitmap.h @@ -17,7 +17,22 @@ struct task_struct; #ifdef CONFIG_X86_IOPL_IOPERM void io_bitmap_share(struct task_struct *tsk); -void io_bitmap_exit(void); +void io_bitmap_exit(struct task_struct *tsk); + +static inline void native_tss_invalidate_io_bitmap(void) +{ + /* + * Invalidate the I/O bitmap by moving io_bitmap_base outside the + * TSS limit so any subsequent I/O access from user space will + * trigger a #GP. + * + * This is correct even when VMEXIT rewrites the TSS limit + * to 0x67 as the only requirement is that the base points + * outside the limit. + */ + this_cpu_write(cpu_tss_rw.x86_tss.io_bitmap_base, + IO_BITMAP_OFFSET_INVALID); +} void native_tss_update_io_bitmap(void); @@ -25,11 +40,12 @@ void native_tss_update_io_bitmap(void); #include <asm/paravirt.h> #else #define tss_update_io_bitmap native_tss_update_io_bitmap +#define tss_invalidate_io_bitmap native_tss_invalidate_io_bitmap #endif #else static inline void io_bitmap_share(struct task_struct *tsk) { } -static inline void io_bitmap_exit(void) { } +static inline void io_bitmap_exit(struct task_struct *tsk) { } static inline void tss_update_io_bitmap(void) { } #endif |